In recent years air travel has seen a large increase in demand. An ever increasing number of people are choosing air travel for business trips as well as for reaching holiday destinations. Business people, in general, choose air travel because of the time savings, reaching their destination within hours instead of days—for tourists it is the ability to reach far destinations in a short time and at relatively low cost. Due to the large increase in air travel most airports all over the world are operating close to the limits of their capacity and, therefore, need to expand. However, building new airports or airport terminals is a very costly and time consuming process. For example, the time period from the first planning stages to completion of the construction extends normally over more than a decade. Therefore, the capacity of numerous airports has to be increased by temporarily expanding the existing infrastructure. For example, in order to be able to service more aircraft an existing airport terminal is expanded by adding one or more gates with associated airplane embarking/disembarking locations. Often passenger loading bridges are employed to provide a path from the gate to the airplane.
However, adding large power consumers such as a passenger loading bridge to an existing airport terminal generally requires an expansion of existing power feed lines to the airport terminal adding considerable infrastructure costs.
Currently, passenger loading bridges are connected to a 600 Amp feed line. The 600 Amp feed line is then branched off into smaller 200 Amp feed lines for providing power to various operational systems of the loading bridge. Typically loading bridges are equipped with drive mechanisms, preconditioned air systems and ground power units. Therefore, the electrical power received from the 600 Amp power feed line is distributed into three 200 Amp sections of the power distribution network of the passenger loading bridge servicing the drive mechanisms, the preconditioned air systems and the ground power units, respectively. The main feed line and the branched off feed lines are dimensioned for the operational case that all functions are used at a same time. Furthermore, the feed lines are also dimensioned to allow for spikes in the power consumption, for example, caused by a starting electric motor of a drive mechanism of the loading bridge. As is evident, in such a power distribution network the infrastructure is not used economically. For example, when the loading bridge is moved to connect to or disconnect from an aircraft no ground power is provided to the aircraft. Furthermore, it is not necessary to operate the preconditioned air system at full capacity. Therefore, less than 400 Amp are used of the 600 Amp power line. In the other case, when the loading bridge is connected to an aircraft the preconditioned air system provides heating or air-conditioning to the aircraft and ground power is provided to the aircraft. However in this case the drive mechanisms are not in use. Therefore, only a maximum of 400 Amp are used of the 600 Amp power line.
Power management systems are known in the art. For example, so called “Power Miser Systems” selectively switch provision of power to different electrical circuits having different power consuming appliances connected thereto in order to reduce peak power consumption. These power management systems manage a limited supply of power by allowing, for example, in a household to operate only an electrical stove, a washing machine or a dryer at a time. However, such power management systems are very inflexible by just switching OFF/ON provision of power to an electrical circuit and are not useful for many applications where it is not possible to just switch between provision of power to one or another electrical circuit.
Another example is power management systems used in battery operated devices such as laptop computers for switching between an operational mode and a sleep mode in order to conserve the limited energy supply of a battery. Though these power management systems conserve battery power, they do not provide a solution to a problem of operating a plurality of electrical circuits with a limited supply of power.
It would be advantageous to have power allocation control for passenger loading bridges capable of managing situations of overdemand such that the passenger loading bridge is operable in a predetermined mode of operation without exceeding a limited amount of power. This allows, for example, for a considerable expansion of an existing airport without upgrading power feed lines connecting the airport to a power provider as well as a majority of power feed lines distributing power within the airport. Therefore, infrastructure cost for expanding an airport terminal would be considerably reduced.
It is, therefore, an object of the invention to provide power allocation control for a passenger loading bridge capable of managing situations of overdemand such that the passenger loading bridge is operable in a predetermined mode of operation without exceeding a limited amount of power available.
It is further an object of the invention to provide power allocation control for a plurality of passenger loading bridges capable of managing situations of overdemand such that each of the plurality of passenger loading bridges is operable in its predetermined mode of operation without exceeding a limited amount of power available.